Draft gear and spring seat therefor



Sept. 11, 1934. D. F. SPROUL 1,972,957

DRAFT GEAR AND SPRING SEAT THEREFOR Original Filed June 8, 1952 I fiver-Lion Patented Sept.

UNITED STATES? DRAFT GEAR AND SPRING SEAT THEREFOR Donald F. Sproul, Chicago, Ill., assignor to Cardwell Westinghouse Company, a corporation of Delaware Continuation of applic ation Serial No. 615,969,

June 8, 1932. This application March 17, 1933;

Serial No. 661,271

5 Claims.

This application is a continuation of and substitute for my abandoned application based 'on the same invention, filed June 8, 1932, Serial No. 615,969.

The invention relates to improvements in draft gears of the Cardwell-type, and in the spring seats used in such gears. I i

It is the practice to provide draft gears with means for limiting compression and sustaining the loads which are beyond the capacity'of the cushioning mechanism, such means comprising one or more rigid elements acting as acolumn. On the installation or adjustment of gears of the Cardwell type it sometimes happens that an inexperienced workman Will place the springs under a too great initial compression; with the result that the springs are solidly closedbefore the solid parts of the gear, which are intended to act as limiting stops and sustain the overload, are

brought into engagement to perform this duty. Under such circumstances there is great danger that other parts of the gear will be broken or otherwise injured.

The object of this invention is to eliminate such .Zdanger of injury to the gear by providing a spring seat which will yield longitudinally under excessive load, thereby making an automatic adjustment to proper length. The seat will then function properly after such distortion.

A preferred embodiment of the invention is hereinafter described, and is illustrated in the accompanying drawing, in which Fig. 1 is a detail plan view, partly in section, of the underframing of a car and of a Cardwell draft gear;

Fig. 2 is a detail longitudinal section, partly in plan, of one end portion of the spring rod of the gear and of the elements carried thereby;

Fig. 3 is a longitudinal central section of the improved spring seat viewed in perspective;

Fig. 4 is a longitudinal central section of the spring seat after having been shortened by the bending of a yieldable portion, due to overload; and

Fig. 5 is a longitudinal section of an outer spring seat embodying the features of improvement.

In Fig. 1 there is shown a typical Cardwell type draft gear applied to the underframing of a car. At 11 are shown a pair of center or draft sills;

at 12 a pair of draft lugs; and at 13 a pair of bufiing lugs. The coupler butt is designated 14,

and the yoke or extension of the coupler is shown The draft gear comprises a pair of chambered followers 16,- 17, and a central wedge element 18.

A pair of triangular wedge-blocks 19 are-seated against the inner transverse face-of each of the followers, and-engage wedge faces on the-element 18. A pair of wedge-blocks, as 20; each engages the outer face of a triangular wedge-block of each pair. The elements 18"and 20 are of suitable length to serve as'limiting stops by making contact with the transverse walls of the followers as the limit of the cushioning capacity is" approached. V r

A spring ortension rod- 21 extends transversely 23 are in threaded engagement with the rod 21 and may be adjustably positioned thereon to maintain a desirable initial compression of the springs 22, 27, a cotter pin 25 being set through the rod.- to prevent the spring seat from backing off after its adjustment.

The outer spring seat 23 is illustrated in Fig. 2 as of ordinary form, having a flat annular seat 26 for the springs 22 and 2'7.

The invention is preferably incorporated in the inner spring seat, which is interposed between the springs and the gear element 20, is sleeved so as to slide upon the rod 21, and comprises a tubular body portion 28, and a plate 29 which constitutes the bearing face for the ends of the springs, these two elements being integrally connected by means of a radial web 30, projecting from the outer end of the tubular body 28 and being inclined forwardly and joined to the plate 29, preferably adjacent to its outer margin. The web 30 is thinner than the plate 29, but is of sufficient strength to sustain loads within the cushioning capacity of the gear, but will yield under more excessive loads to permit the shortening of the seat by bringing the plate 29 toward the body portion 28.

Differently described, the spring seat comprises the tubular body 28 and a radial flange at its outer end, the inner face of the flange being circumferentially channeled. This spring seat is preferably made of a metal which will distort without breakage.

In installing the gear good practice requires that the outer spring seat 23 be turned up to put the springs under slight compression, but leaving them of such length that they will not be fully compressed when the closing of the gear is arrested by the engagement of the elements 18 and 20 with the transverse walls of the followers. It not infrequently happens that the initial compression of the springs has been too great, shortening them to such an extent that they are fully closed before the solid elements, which are intended to act as limiting stops, are brought into action as such, with the result that the overload is sustained by the springs and their associated parts and breakage occurs.

The present invention prevents such injury; the spring seat being shortened by the bending of the web 30, as indicated in Fig. 4, and thus automatically correcting the faulty initial adjustment.

In practice the spacing of the plate 29 from the end of the body 28 may be ample to insure a proper readjustment without bringing the members 28, 29, into actual contact. This is quite feasible, as the yielding will occur at both ends of the rod.

Should it be desired to provide for this automatic readjustment at the outer end of the springs, the outer spring seat may take the form shown in Fig. 5, the body portion 2 8 being in the formof a nut instead of a sliding sleeve. Following good practice the plateZQ which constitutes the seat proper, is annularly channeled, as shown at 29*, to provide for slightly less compression of the inner spring than for the outer one, the two springs being of equal length.

I claim as my invention 1. In a draft gear, in combination, a pair of chambered followers, a group of cooperating friction and wedging elements enclosed between the followers and being laterally expansible on the relative approach of the followers, a tensionrod extending through the laterally outward elements ofthe group, a pair ofspring seats mountedon each end portion of the rod, one thereof being fixed and the other being slidable onthe rod and comprising a tubular body bearing upon one of the last-mentioned elements and an annular plate for engaging a spring and facing and being spaced from the body, a collapsible web extending radially from the body and supporting the plate, and a spring reacting between the two spring seats on each end of the rod.

2. In a draft gear, in combination, a pair of chambered followers, a group of cooperating friction and wedging elements enclosed between the followers and being laterally expansible on the relative approach of the followers, a tension rod extending through the laterally outward elements of the group, a pair of spring seats mounted on each end portion of the rod, one thereof being fixed and the other being slidable on the rod, one of such seats comprising a tubular body, an annular plate spaced from the body for engaging a spring and a collapsible web extending radially from the body and supporting the plate, and a spring reacting between the spring seats on each end of the rod. v p

3. A spring seat formed of flexible non-resilient material and having a portion yieldable only under excessive loads for shortening the body of the seat. 100

4. A spring seat of non-resilient material having a portion so formed, constructed and arranged that it is collapsible within such portion under an excessive load to permanently shorten the body of the seat without destroying its normal func- 1&5 tioning.

5. A spring seat adapted to be'permanently shortened in length under an excessive load without destroying its normal functioning, said seat comprising a tubular body of non-resilient ma- 11c terial having an intermediate portion formed as a hollow flange and arranged to permit the walls of said flange to collapse toward each other to obtain such shortening of the spring seat.

1 DONALD F. SPROUL. 

